Melt the butter over med. heat in a large heavy pot or Dutch oven. Add half of the meat in a single layer and cook 3-4 minutes on each side, until browned. Transfer to a plate and brown the remaining pieces. Return all meat to the pot, sprinkle with salt, pepper, and flour, and stir to coat. Add the onions and stir; the pot will seem quite full. Cook for 5 minutes, stirring regularly to avoid coloring.

Pour in 250ml warm water and scrape the bottom of the pan with a wooden spoon to deglaze. Pour in the beer and an additional 250ml water; stir, and bring to a simmer.

Add the sugar, thyme, bay leaves, and cloves, and stir. Lower the heat to med. low; cover, and simmer for 2 1/2 hours, stirring every once in a while. An hour into the cooking, spread each slice of bread with a tablespoon of mustard and place at the surface of the stew. The bread will soon be moistened by the steam inside the pot and will fall apart as you stir, giving body to the sauce.

Remove the lid, turn the heat up to medium-high, and cook for 20 more minutes, stirring regularly, until the sauce is thick enough to cling to the meat. Serve hot from the pot, with small steamed potatoes.

**Note: I neglected to stir this frequently enough during the last hour of cooking and it started to stick to the bottom of the pan. I saved it, but it would have been a lot better if that hadn't happened. I'll be more careful next time.